Pumping system, pumping system valve, replacement kit for a valve, and related manufacturing method

ABSTRACT

A valve for controlling a flow of fluid to a pump is disclosed. The valve includes a first member and a second member. The first member includes a first surface and an inlet opening, a first opening, a second opening, and an outlet opening extending through the first surface. The second member includes a second surface in contact with the first surface. The second member is movable relative to the first member between a first position and a second position while maintaining the first and second surfaces in contact with each other. At least one of the first surface and the second surface is made of a self-lubricating material. In the first and second positions, the second member allows selective flow communication among the inlet, first, second, and outlet openings and controls a flow into and out of the pump.

BACKGROUND OF THE INVENTION

[0001] This invention generally relates to a pumping system, a pumpingsystem valve, a replacement kit for a valve, and a related manufacturingmethod. More particularly, the present invention relates to a pumpingsystem including a pump and a valve controlling the flow of fluid to thepump, a replacement kit for the control valve, and a related method ofmanufacturing the replacement kit.

[0002] Conventional pumping systems are used for delivering liquid, suchas glycol, into a natural gas pipeline. Typically, the pump in suchpumping systems is a pneumatically-driven pump deriving its motive powerfrom pressurized natural gas flowing through the natural gas pipeline. Avalve connected to the pneumatically-driven pump controls the flow ofnatural gas into the pneumatically-driven pump and as well as the flowof discharge natural gas exiting out of the pneumatically-driven pump.The valve is typically a rotary valve and includes a valve body and avalve member rotatable within a bore of the valve body. Because thevalve body and the valve member are made of metal, a gap (e.g.,{fraction (1/3000)} inch gap) exists between the bore of the valve bodyand the valve member to prevent binding and galling between them.Through this gap, however, some of the natural gas “blows-by” and neverassists in motivation of the pneumatically-driven pump.

[0003] In addition to consuming more natural gas than necessary, theconventional pumping system with this “blow-by” problem raises manyenvironmental typically exhausted to the environment. Accordingly, thereis a need in the art to minimize the amount of natural gas exhausted tothe environment. There is also a related need to reduce the cost ofoperating a pump driven by natural gas.

SUMMARY OF THE INVENTION

[0004] The present invention is directed to a pumping system, a pumpingsystem valve, a replacement kit for a valve, and a related manufacturingmethod. The advantages and purposes of the invention will be set forthin part in the description which follows, and in part will be obviousfrom the description, or may be learned by practice of the invention.The advantages and purposes of the invention will be realized andattained by the elements and combinations particularly pointed out inthe appended claims.

[0005] In accordance with the invention, a pumping system comprises apump, a fluid source, and a valve. The pump includes a first port and asecond port. The fluid source provides motive power to the pump. Thevalve is connected to the fluid source and the pump. The valve includesa first member and a second member. The first member includes a firstsurface and an inlet opening, a first opening, a second opening, and anoutlet opening extending through the first surface. The inlet opening,the first opening, and the second opening are respectively in flowcommunication with the fluid source, the first port of the pump, and thesecond port of the pump. The second member includes a second surface incontact with the first surface. The second member is movable relative tothe first member between a first position and a second position whilemaintaining the first and second surfaces in contact with each other.The second member is configured to allow flow communication,respectively, between the inlet opening and the first opening andbetween the second opening and the outlet opening in the first position.The second member is also configured to allow flow communication,respectively, between the inlet opening and the second opening andbetween the first opening and the outlet opening in the second position.At least one of the first surface and the second surface is made of aself-lubricating material.

[0006] In another aspect, the invention is directed to a valvecomprising a first member and a second member. The first member includesa first surface and an inlet opening, a first opening, a second opening,and an outlet opening extending through the first surface. The secondmember includes a second surface in contact with the first surface. Thesecond member is movable relative to the first member between a firstposition and a second position while maintaining the first and secondsurfaces in contact with each other. The second member is configured toallow flow communication, respectively, between the inlet opening andthe first opening and between the second opening and the outlet openingin the first position. The second member is also configured to allowflow communication, respectively, between the inlet opening and thesecond opening and between the first opening and the outlet opening inthe second position. At least one of the first surface and the secondsurface is made of a self-lubricating material.

[0007] In yet another aspect, the invention is directed to a replacementkit for a valve. The valve includes a divider movable between a firstposition and a second position. The divider includes a surface. Thereplacement kit includes a member including a contact surface. Themember further includes an inlet opening, a first opening, a secondopening, and an outlet opening extending though the contact surface. Thecontact surface is made of a self-lubricating material and is configuredto be in contact with the surface of the divider while the divider movesbetween the first position and the second position. In the firstposition, the divider allows flow communication, respectively, betweenthe inlet opening and the first opening and between the second openingand the outlet opening. In the second position, the divider allows flowcommunication, respectively, between the inlet opening and the secondopening and between the first opening and the outlet opening in thesecond position.

[0008] In yet another aspect, the invention is directed to a method ofmanufacturing a replacement kit for a valve. The valve includes adivider movable between a first position and a second position. Thedivider includes an outer surface. The method comprises: preparing avalve body including a bore, the valve body further including an inlethole, a first hole, a second hole, and an outlet hole extending to thebore; preparing a bushing made of a self-lubricating material, thebushing including an outer surface and an initial inner surface; fittingthe bushing within the bore of the valve body such that the outersurface of the bushing is in contact with the bore of the valve body;and cutting the initial inner surface of the bushing to form a finalinner surface sized to be in contact with the outer surface of thedivider while the divider moves between the first position and thesecond position.

[0009] Additional objects and advantages of the invention will be setforth in part in the description which follows, and in part will beobvious from the description, or may be learned by practice of theinvention. The objects and advantages of the invention will be realizedand attained by means of the elements and combinations particularlypointed out in the appended claims.

[0010] It is to be understood that both the foregoing generaldescription and the following detailed description are exemplary andexplanatory only and are not restrictive of the invention, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are incorporated in andconstitute a part of this specification, illustrate embodiments of theinvention and together with the description, serve to explain theprinciples of the invention. In the drawings,

[0012]FIG. 1 is a schematic drawing of an embodiment of a pumping systemaccording to the invention, showing a movable member of a valve in afirst position;

[0013]FIG. 2 is a schematic drawing of the pumping system of FIG. 1,showing the movable member of the valve in a second position;

[0014]FIG. 3 is an exploded view of an embodiment of a valve accordingto the invention;

[0015]FIG. 4 is a perspective view of the valve of FIG. 3;

[0016]FIG. 5 is another perspective view of the valve of FIG. 3;

[0017]FIG. 6 is a sectional view of a valve body according to theinvention;

[0018]FIG. 7 is a side view of a tubular bushing according to theinvention;

[0019]FIG. 8 is a front view of a bonnet according to the invention;

[0020]FIG. 9 is a sectional view of the valve of FIG. 3, illustrating ashaft attached to a component of a trip assembly; and

[0021]FIG. 10 is an exploded view of the valve of FIG. 3 and a tripassembly according to the invention.

DETAILED DESCRIPTION

[0022] Reference will now be made in detail to embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

[0023] For the purposes of the following descriptions, “aself-lubricating material” refers to a material requiring no externallubrication when it, or another material in contact with it, movesrelative to the other.

[0024] As embodied herein and illustrated in FIGS. 1 and 2, a pumpingsystem 20 includes a pump 22. The pump 22 may be used for pumping alltypes of fluid to a pumping destination 28. The types of fluid to bepumped to the pumping destination 28 include, but are not limited to,liquid such as water, glycol, and other chemical solutions and gasessuch as air and natural gas. However, the pump 22 will be describedhereinafter in connection with pumping liquid to the pumping destination28.

[0025] The liquid to be pumped enters the pump 22 through a liquid inlet24 of the pump 22 and exits through a liquid outlet 26 of the pump 22toward the pumping destination 28. The liquid is supplied to the pump 22from any conventional source, including but not limited to a storagetank and a conduit. Similarly, the pumping destination 28 may be anyconventional location or structure, including but not limited to, anatural gas pipeline, a storage tank, and a conduit.

[0026] Many different types of pumps, including but not limited to, apneumatically-driven pump, a hydraulically-driven pump, and anelectrically-driven pump, may be utilized in the pumping system 20. Inan embodiment utilizing a hydraulically-driven pump or apneumatically-driven pump, the pumping system 20 includes a fluid source30 providing the necessary motive power to operate the pump 22. Thefluid source 30 may utilize many different types of fluid, including butnot limited to, liquid such as water or gases such as natural gas andair. In the embodiment illustrated in FIGS. 1 and 2, the pump 22 is apneumatically-driven pump and the fluid source 30 is a pneumatic sourceproviding many different types of gas, including but not limited to,natural gas and air, to the pump 22. The pneumatic source 30 may becompressed fluid from a compressor or may be pressurized natural gasfrom a natural gas pipeline. Accordingly, a natural gas pipeline 32designated by the phantom lines in FIGS. 1 and 2 may both provide thepneumatic source 30 and serve as the pumping destination 28. In otherwords, the pump 22 may derive its motive power from the natural gaspipeline 32 and, at the same time, pump liquid to the natural gaspipeline 32.

[0027] As illustrated in FIGS. 1 and 2, the pumping system 20 mayinclude a pressure reducer 36 and a flow regulator 38. The pressurereducer 36 and the flow regulator 38 may be installed between thepneumatic source 30 and the pump 22 in the order shown in FIGS. 1 and 2or they may be installed in a reverse order.

[0028] The pumping system 20 may include the pressure reducer 36 if thepressure of the gas of the pneumatic source 30 is greater than thenecessary pressure to operate the pump 22. The pump 22, however, maystill operate if the pressure of the gas of the pneumatic source 30 isgreater than the necessary pressure to operate the pump 22. Accordingly,the pumping system 20 may not need the pressure reducer 36 if thepressure of the gas of the pneumatic source 30 is greater than thenecessary pressure to operate the pump 22, although in this case thepump 22 may run faster than required.

[0029] A variety of known and commercially available devices, includingbut not limited to, conventional valves, may be used as the pressurereducer 36. The pressure reducer 36 may be of a fixed-pressure type tobe used with a pneumatic source of a fixed pressure and a pump requiringanother fixed pressure. Alternatively, the pressure reducer 36 may be avariable-pressure type capable of being used with different pneumaticsources 30 supplying gases at different pressures. Also, the pressurereducer 36 may be a variable-pressure type capable of being used withdifferent pumps requiring gases at different pressures.

[0030] Similarly, the pumping system 20 may include the flow regulator38 if the amount of gas from the pneumatic source 30 is greater than thenecessary amount to operate the pump 22. The pump 22, however, may stilloperate if the amount of the gas from the pneumatic source 30 is greaterthan the necessary amount to operate the pump 22. Accordingly, thepumping system 20 may not need the flow regulator 38 if the gas from thepneumatic source 30 is greater than the necessary amount to operate thepump 22, although in this case too the pump 22 may run faster thanrequired.

[0031] A variety of known and commercially available devices, includingbut not limited to conventional valves, may be used as the flowregulator 38. The flow regulator 38 may be of a fixed-amount type to beused with a pneumatic source supplying a fixed amount of gas and a pumprequiring another fixed amount of gas. Alternatively, the flow regulator38 may be a variable-amount type capable of being used with differentpneumatic sources supplying different amounts of gas. Also, the flowregulator 38 may be a variable-amount type capable of controlling theamount of gas supplied to different pumps at different levels.

[0032] Furthermore, instead of including separate devices for reducingthe pressure of the gas from the pneumatic source 30 and controlling theamount of gas supplied to the pump 22, the pumping system 20 may includea single device serving both as the pressure reducer 36 and as the flowregulator 38.

[0033] As illustrated in FIGS. 1 and 2, the pump 22 includes a cylinder42 and a piston 40 movably fitted within the cylinder 42. A plunger 44extends from the piston 40 and a part of the plunger 44 is accommodatedwithin a chamber 48. The pump 22 further includes a first check valve 50and a second check valve 52. The chamber 48 is in flow communicationwith the first check valve 50 through the liquid inlet 24 and with thesecond check valve 52 through the liquid outlet 26.

[0034] In response to the gas supplied to the pump 22, the piston 40moves in a reciprocating motion. The plunger 44 moves in a reciprocatingmotion in response the reciprocating motion of the piston 40. As theplunger 44 moves away from the first and second check valves 50 and 52(FIG. 2), the liquid to be pumped enters the chamber 48 through thefirst check valve 50 and the liquid inlet 24. The check valve 52 remainsclosed while the plunger 44 moves away from the first and second checkvalves 50 and 52. Subsequently, as the plunger 44 moves toward the firstand second check valves 50 and 52 (FIG. 1), it pushes the liquid in thechamber 48 out through the liquid outlet 26 and the check valve 52 andtherefore pumps the liquid to the pumping destination 28. The checkvalve 50 remains closed while the plunger 44 moves toward the first andsecond check valves 50 and 52. The plunger 44 repeats this reciprocatingmotion to pump the liquid to the pumping destination 28. As describedabove, the pumping destination 28 may be a natural gas pipeline and theliquid to be pumped to the pumping destination 28 may be glycol.

[0035] The pump 22 further includes a first port 32 and a second port 34allowing the entrance and exit of the gas. The fresh gas supplied fromthe pneumatic source 30 enters the cylinder 42 of the pump 22 throughone of the first and second ports 32 and 34 and the discharge gas fromthe cylinder 42 of the pump 22 exits through the other of the first andsecond ports 32 and 34. FIG. 1 illustrates the fresh gas entering thecylinder 42 through the first port 32. The fresh gas pushes the piston40 and the plunger 44 toward the first and second check valve 50 and 52and pumps liquid to the pumping destination 28. As the plunger 44 pumpsliquid to the pumping destination 28, the discharge gas exits thecylinder 42 through the second port 34.

[0036]FIG. 2 illustrates the fresh gas entering the cylinder 42 throughthe second port 34. The fresh gas pushes the piston 40 and the plunger44 away from the first and second check valve 50 and 52 and draws theliquid into the chamber 48. As the plunger 44 draws the liquid into thechamber 48, the discharge gas exits the cylinder 42 through port 32.

[0037] As embodied herein and illustrated in FIGS. 1 and 2, the pumpingsystem 20 further includes a valve 60 connected to the pump 22 and thepneumatic source 30. The valve 60 controls the flow of fresh gas intothe cylinder 42 and the flow of discharge gas exiting out of thecylinder 42.

[0038] The valve 60 includes a first member 62 and a second member 64.The first member 62 includes a first surface 63 and an inlet opening 70,a first opening 72, a second opening 74, and an outlet opening 76extending through the first surface 63. The inlet opening 70 is in flowcommunication with the pneumatic source 30 through the pressure reducer36 and the flow regulator 38. The first and second openings 72 and 74are respectively in flow communication with the first and second ports32 and 34 of the pump 22. The outlet opening 76 may be in fluidcommunication with the environment. Accordingly, the discharge gasexiting the cylinder 42 of the pump 22, conventionally called exhaust,may be, totally or partially, released to the environment directlythrough the valve 60.

[0039] Instead of being released to the environment directly, theexhaust may be, totally or partially, utilized in other systems beforebeing released to the environment. Furthermore, the exhaust may be,totally or partially, looped back to the pumping system 20. For example,if the pumping system 20 utilizes the natural gas in the natural gaspipeline 32 as the pneumatic source, the exhaust may be, totally orpartially, looped back to the natural gas pipeline 32 after beingsubjected to appropriate treatment. Also, the exhaust may be, totally orpartially, utilized in a line heater or in a reboiler burner.

[0040] The second member 64 of the valve 60 includes a second surface 65in contact with the first surface 63 of the first member 62. Asillustrated in FIGS. 1 and 2, the second member 64 is movable between afirst position (FIG. 1) and a second position (FIG. 2) while maintainingthe second surface 65 in contact with the first surface 63 of the firstmember 62. The valve 60 illustrated in FIGS. 1 and 2 shows a rotaryvalve where the second member 64 is rotatable between the first andsecond positions. As described in greater detail below, the secondmember 64 rotates between the first and second positions in response tothe reciprocating motion of the plunger 44 of the pump 22. A travel stop45 is provided on the plunger 44 to operate a trip assembly, which isconnected to the second member 64 to rotate it between the first andsecond positions. The details of the trip assembly and its operation incooperation with the travel stop 45 are described in greater detailbelow.

[0041] Other types of valves beside a rotary valve, however, may be usedin the pumping system 20. For example, the first and second members maybe configured such that the second member moves in a linear motion,instead of in a rotating motion, while maintaining contact between thefirst and second members. Also, other types of pumps beside the pump 22may be used in the pumping system 20. For example, a pump including areplacement piston and a replacement cylinder may be used in the pumpingsystem 20. Also, a double-acting pump, pumping twice the amount ofliquid per pump cycle than the pump 22, may be used in the pumpingsystem 20. A copending U.S. patent application Ser. No. 10/162,747discloses a single-acting pump, a double-acting pump, and a pump with areplacement piston and a replacement cylinder. The descriptions of U.S.patent application Ser. No. 10/162,747 regarding these types of pumpsare incorporated herein by reference.

[0042] For the purposes of illustrating the second surface 65, FIGS. 1and 2 show a gap between the first and second surfaces 63 and 65. Inreality, however, the gap shown in FIGS. 1 and 2 does not exist. Asdescribed above, the first and second surfaces 63 and 65 are in contactwith each other while the second member 64 moves between the first andsecond positions. Because no gap exists between the first and secondsurfaces 63 and 65, the valve of the present invention eliminates orsubstantially reduces gas loss due to “blow-by.” In other words, thecontact between the first and second surfaces 63 and 65 ensures thatvirtually no fresh gas entering the inlet opening 70 of the valve 60exits through the outlet opening 76 without first entering the cylinder42 of the pump 22. By eliminating or substantially reducing this“blow-by” loss of a conventional valve, the valve of the presentinvention reduces gas consumption of the pump 22. Furthermore, theelimination or substantial reduction of the “blow-by” loss lowers therequired supply pressure of the gas to operate the pump 22. Accordingly,for a given pumping requirement, the valve of the present inventionallows an operator to lower the supply pressure setting of the pressurereducer 36 below that required in a pumping system utilizing aconventional valve.

[0043] In the first position illustrated in FIG. 1, the second member 64allows flow communication, respectively, between the inlet opening 70and the first opening 72 of the first member 62 and between the secondopening 74 and the outlet opening 76 of the first member 62.Accordingly, the fresh gas supplied from the pneumatic source 30 entersthe cylinder 42 of the pump 22 through the inlet opening 70 and thefirst opening 72 of the first member 62 and through the first port 32 ofthe pump 22 while the discharge gas is released through second port 34of the pump 22 and through the second opening 74 and the outlet opening76 of the first member 62.

[0044] In the second position illustrated in FIG. 2, the second member64 allows flow communication, respectively, between the inlet opening 70and the second opening 74 of the first member 62 and between the firstopening 72 and the outlet opening 76 of the first member 62.Accordingly, the fresh gas supplied from the pneumatic source 30 entersthe cylinder 42 of the pump 22 through the inlet opening 70 and thesecond opening 74 of the first member 62 and through the second port 34of the pump 22 while the discharge gas is released through first port 32of the pump 22 and through the first opening 72 and the outlet opening76 of the first member 62.

[0045] To facilitate the movement of the second member 64 without anyexternal lubrication, at least one of the first surface 63 or the secondsurface 65 is made of a self-lubricating material. For example, eitherthe first member 62 or the second member 64 as a whole may be made of aself-lubricating material. Alternatively, either the first member 62 orthe second member 64 may be coated with a self-lubricating material ifit has appropriate bonding characteristics.

[0046] A self-lubricating material prevents the binding and galling thatwould normally occur if first and second surfaces, both made of metal(e.g., steel) and in contact with each other, move relative to eachother without external lubrication. A self-lubricating material may haveflexibility to maintain contact between the first and second surfaces 63and 65 through changing operating conditions of the valve 60. Aself-lubricating material may also have wearability to accommodatemanufacturing inconsistencies of the first and second members 62 and 64.Excessive wearability, however, may shorten the operating life of thevalve 60. These competing factors, i.e., flexibility and wearability,determine which self-lubricating material is appropriate for givenoperating conditions and required operating life of the valve 60.

[0047] Many PTFE (polytetrafluoroethylene)-based materials may be usedas a self-lubricating material. For example, materials, such as carbon,graphite, and bronze, may be mixed with PTFE, such as Teflon®, to form aself-lubricating material. Also, glass may also be mixed with PTFE toform a self-lubricating material. PTFE may act as a carrier in thesematerials. These mixtures are preferably homogenous, but heterogeneousmixtures may also be used.

[0048] In a self-lubricating material made of carbon and PTFE, thecarbon may constitute 10 to 35% of the self-lubricating material byvolume. More than 35% of carbon may be cause excessive wear. On theother hand, a self-lubricating material including less than 10% ofcarbon may be too flexible and may cause excess drag on the movingmember and possible pump stall. Similarly, in a self-lubricatingmaterial made of graphite and PTFE, the graphite may constitute 10 to35% of the self-lubricating material by volume. Preferably, aself-lubricating material made of carbon or graphite and PTFE include 20to 25% of the carbon or graphite by volume.

[0049]FIGS. 3-9 illustrate an embodiment of the valve 60 describedabove. The valve 60 includes a valve body 78. The valve body 78 includesa bore 79 and an inlet hole 80, a first hole 82, a second hole 84, andan outlet hole 86 extending to the bore 79. As described above, thevalve 60 further includes the first member 62. In the embodimentillustrated in FIGS. 3-9, the first member 62 is made in a form of atubular bushing to be fitted within the bore 79 of the valve body 78. Asbest illustrated in FIGS. 6 and 9, each of the inlet hole 80 and theoutlet hole 86 of the valve body 78 is shown to include three holes.However, each of the inlet hole 80 and the outlet hole 86 of the valvebody 78 may have only a single hole or any other number of holes.Similarly, as best illustrated in FIGS. 7 and 9, each of the inletopening 70 and the outlet opening 76 of the tubular bushing 62 is shownto include three openings. However, each of the inlet opening 70 and theoutlet opening 76 of the tubular bushing 62 may have only a singleopening or any other number of openings.

[0050] The tubular bushing 62 includes an outer surface 75 and an innersurface, which is the first surface 63 illustrated in FIGS. 1 and 2. Thetubular bushing 62 further includes a first hole 77 formed between theinner and outer surfaces 63 and 75. The tubular bushing 62 is sized tobe fitted within the bore 79 of the valve body 78 and, when fitted, itsouter surface 75 is in contact with the bore 79. The tubular bushing 62may be fitted within the bore 79 of the valve body 78 by any well-knownmethod including press-fitting. When fitted, the inlet, first, second,and outlet openings 70, 72, 74, and 76 of the tubular bushing 62 arealigned respectively with the inlet, first, second, and outlet holes 80,82, 84, and 86 of the valve body 78.

[0051] As described above, the valve 60 further includes the secondmember 64. In the embodiment illustrated in FIGS. 3-9, the second member64 includes a divider 67 and a shaft 69 extending from the divider 67.The divider 67 includes an outer surface, which is the second surface 65illustrated in FIGS. 1 and 2. The divider 67 is sized to be fittedwithin the inner surface 63 of the tubular bushing 62. As describedabove, the outer surface 65 of the divider 67 is in contact with theinner surface 63 of the tubular bushing 62 while the divider 67 movesbetween the first position (FIG. 1) and the second position (FIG. 2).

[0052] In the embodiment illustrated in FIGS. 3-9, the valve 60 furtherincludes a bonnet 90 secured to the valve body 78. The bonnet 90includes a second hole 92 (FIG. 8) aligned with the first hole 77 of thetubular bushing 62. A pin 94 is positioned in the first hole 77 of thetubular bushing 62 and the second hole 92 of the bonnet 90. Therefore,when the bonnet 90 is secured to the valve body 78 using cap screws 93,the pin 94 ensures that the tubular bushing 62 remains stationary whilethe divider 67 moves between the first and second positions with itsouter surface 65 in contact with the inner surface 63 of the tubularbushing 62. In other words, the pin 94 prevents the tubular bushing 62from rotating should the outer surface 65 of the divider 67 bind on theinner surface 63 of the tubular bushing 62.

[0053] The valve 60 may further include a bonnet gasket 96 to beinterposed between the bonnet 90 and the valve body 78. The bonnetgasket 96 includes holes for the pin 94 and the cap screws 93. The valve60 may further include bearings 97 for facilitating the rotation of thesecond member 64, an o-ring 98 providing a seal between the valve body78 and a box 116 (FIGS. 1 and 2) of the pump 22, and a packing 99providing a seal between the shaft 69 and the valve body 78.

[0054]FIGS. 3-9 illustrate a valve including the tubular bushing 62,made of a self-lubricating material, formed separately from the valvebody 78, and fitted within the bore 79 of the valve body 78. The tubularbushing 62 and the valve body 78, however, may be integrally formed as asingle structure. In addition, the second member 64 may be made of aself-lubricating material instead of the tubular bushing 62.Furthermore, as described above, if a self-lubricating material hasappropriate bonding characteristics, the inner surface 63 or the outersurface 65 may be made of the self-lubricating material and coated onthe rest of the tubular bushing 62 or the divider 67 made of a differentmaterial.

[0055]FIG. 10 illustrates a trip assembly, which in cooperation with thetravel stop 45 of the plunger 44 rotates the second member 64 betweenthe first and second positions. As illustrated, the shaft 69 extendingfrom the divider 67 is connected to a trip assembly 118 included in thebox 116 (FIGS. 1 and 2) of the pump 22. The trip assembly 118 includes abumper 120 and a rod 119 secured to the bumper 120 using a pair ofcotter pins 117. The bumper 120 includes a first stop 144 and a secondstop 146. The trip assembly 118 further includes a trip arm 122 havingfirst and second ends. The shaft 69 of the second member 64 extendsthrough a hole 121 provided in the bumper 120 and is secured to thefirst end of the trip arm 122 using a cap screw 123. The trip assembly118 further includes a trip spring 124 having first and second ends. Thefirst end of the trip spring 124 is secured to the second end of thetrip arm 122 using a clevis pin 125 and a hair pin cotter 126. Asdescribed in greater detail below, the second end of the trip arm 122 isrotatable between the first and second stops 144 and 146 of the bumper120.

[0056] The trip assembly 118 further includes a sleeve 128 havingprojections 136. While the first end of the trip spring 124 is securedto the trip arm 122, the second end of the trip spring 124 is secured tothe projections 136 of the sleeve 128 using a cylindrical pin 138 and apair of cotter pins 140. The sleeve 128 further includes a hole 130 andfirst and second end flanges 132 and 134. The rod 119 is insertedthrough the hole 130 of the sleeve 128 and the first and second endflanges 132 and 134 are sized to selectively engage the travel stop 45of the plunger 44. Accordingly, the sleeve 128 is movable along the rod119 toward and away from the check valves 50 and 52 (to the left andright of FIGS. 1 and 2) as the travel stop 45 of the plunger 44selectively engages the first and second end flanges 132 and 134 of thesleeve 128.

[0057] As described above, while the piston 40 and the plunger 44 moveaway from the first and second check valves 50 and 52 (to the left inFIG. 2), the second member 64 remains in the second position (FIG. 2)and the liquid to be pumped enters the chamber 48 through the firstcheck valve 50. As the piston 40 and plunger 44 near the end of theirmovement away from the first and second check valves 50 and 52, thetravel stop 45 of the plunger 44 engages and pushes the first end flange132 of the sleeve 128 away from the first and second check valves 50 and52. The projections 136 in turn pull and bend the second end of the tripspring 124 away from the first and second check valves 50 and 52.

[0058] When the travel stop 45 of the plunger 44 reaches its leftmostposition, the biasing force generated by the bending of the trip spring124 rotates the first end of the trip spring 124 toward the first andsecond check valves 50 and 52. The trip spring 124 thereby regains itsneutral configuration (i.e., the configuration without any bending). Thesecond end of the trip arm 122, which is secured to the first end of thetrip spring 124, in turn rotates toward the first and second checkvalves 50 and 52 and engages the second stop 146 of the bumper 120.Finally, the shaft 69 of the second member 64, which is secured to thefirst end of the trip arm 122, rotates toward the first and second checkvalves 50 and 52 and rotates the divider 67 of the second member 64 tothe first position (FIG. 1).

[0059] On the other hand, while the piston 40 and plunger 44 move towardthe first and second check valves 50 and 52 (to the right of FIG. 1),the divider 67 of the second member 64 remains in the first position(FIG. 1) and the liquid in the chamber 48 exits through the second checkvalve 52 toward the pumping destination 28. As the piston 40 and plunger44 near the end of their movement toward the first and second checkvalves 50 and 52, the travel stop 45 of the plunger 44 engages andpushes the second end flange 134 of the sleeve 128 toward the first andsecond check valves 50 and 52. The projections 136 in turn pull and bendthe second end of the trip spring 124 toward the first and second checkvalves 50 and 52.

[0060] When the travel stop 45 of the plunger 44 reaches its rightmostposition, the biasing force generated by the bending of the trip spring124 rotates the first end of the trip spring 124 away from the first andsecond check valves 50 and 52. The trip spring 124 thereby regains itsneutral configuration. The second end of the trip arm 122, which issecured to the first end of the trip spring 124, in turn rotates awayfrom the first and second check valves 50 and 52 and engages the firststop 144 of the bumper 120. Finally, the shaft 69 of the second member64, which is secured to the first end of the trip arm 122, rotates awayfrom the first and second check valves 50 and 52 and rotates the divider67 of the second member 64 back to the second position (FIG. 2). At thispoint, a single pump cycle is completed and the next pump cycle begins.

[0061] In accordance with the invention, a replacement kit may beprovided. The replacement kit may be used to retrofit an existing valve.For example, a replacement kit for an existing valve may include thevalve body 78, the tubular bushing 62, the bonnet 90, the bonnet gasket96, and the pin 94. The second member 64, the bearings 97, the o-ring98, and the packing 99 of the exiting valve may be reused. Thereplacement kit may have the tubular bushing 62 already fitted withinthe bore 79 of the valve body 78. Alternatively, the tubular bushing 62may be provided separately from the valve body 78.

[0062] Subsequently, when the tubular bushing 62 wears out and its innersurface 63 no longer provide contact with the outer surface 65 of thedivider 67, it may be replaced with a new tubular bushing. An end usermay realize a worn-out tubular bushing when the liquid output of thepump 22 decreases below a certain level. For example, as the tubularbushing wears out, the liquid output of the pump 22 may decrease fromits initial value of 20 gpm to 16 gpm due to the gas “blow-by.” Theseexemplary values are provided solely for the purpose of explanation andshould not be construed to limit the scope of the invention. Dependingon the types of pumps utilized, these values may vary.

[0063] The new tubular bushing may be provided as fitted within the bore79 of the valve body 78. For example, in exchange for a used valve bodyand a worn-out tubular bushing, a replacement kit manufacturer mayprovide an end user a new valve body and a new tubular bushing alreadyfitted within the bore of the new valve body. Alternatively, areplacement kit manufacturer may provide only a new tubular bushing andan end user may replace a worn-out tubular bushing with the new tubularbushing.

[0064] Therefore, in accordance with the invention, a replacement kitfor a valve may include a tubular bushing alone, a tubular bushing and avalve body provided separately, or a tubular bushing already fittedwithin a bore of a valve body. As needed, a replacement kit may furtherinclude any one or combination of a bonnet, a bonnet gasket, a pin, asecond member, bearings, a packing, or an o-ring.

[0065] In accordance with the invention, a replacement kit may bemanufactured to include a tubular bushing fitted within a bore of avalve body. A replacement kit manufacturer may prepare the valve body 78by either manufacturing it or obtaining it from an end user or a partsupplier. The replacement kit manufacturer may also prepare the tubularbushing 62 by either manufacturing it or obtaining it from a partsupplier. The outer surface 75 of the tubular bushing 62 may be sized tocontact the bore 79 of the valve body 78. The initial inner surface ofthe tubular bushing 62, however, may be smaller than the size necessaryto have a contact with the outer surface 65 of the divider 67. Afterfitting the tubular bushing 62 within the bore 79 of the valve body 78,the replacement kit manufacturer may cut the initial inner surface toform a final inner surface. This cutting may be performed by any knownmethod including milling. The final inner surface is sized to be incontact with the outer surface 65 of the divider 67.

[0066] A smaller initial inner surface may be necessary because thetubular bushing 62, made of a self-regulating material, may deform whilebeing fitted within the bore 79 of the valve body 78. By starting with asmaller initial inner surface and cutting it to a final inner surface,the replacement kit manufacturer may maintain the close tolerancerequired to provide a contact between the outer surface 65 of thedivider 67 and the final inner surface.

[0067] After cutting the initial inner surface to the final innersurface, the replacement kit manufacturer may form the inlet, first,second, and outlet openings 70, 72, 74, and 76 through the tubularbushing 62 by drilling them through the inlet, first, second, and outletholes 80, 82, 84, and 86 of the valve body 78. Alternatively, the inlet,first, second, and outlet openings 70, 72, 74, and 76 may be formedfirst before cutting the initial inner surface to the final innersurface.

[0068] The replacement kit manufacturer may further form the first hole77 between the final inner surface and the outer surface 75 of thetubular bushing 62. The replacement kit manufacturer may also preparethe bonnet 90 by either manufacturing it or obtaining it from a partsupplier and form the second hole 92 to be aligned with the first hole77 of the tubular bushing 62. Furthermore, the replacement kitmanufacturer may prepare other components such as the bonnet gasket 96with its holes for the pin 94 and the cap screws 93.

[0069] It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope or spirit of the invention. Otherembodiments of the invention will be apparent to those skilled in theart from consideration of the specification and practice of theinvention disclosed herein.

What is claimed is:
 1. A pumping system, comprising: a pump including afirst port and a second port; a fluid source providing motive power tothe pump; and a valve connected to the fluid source and the pump, thevalve comprising: a first member including a first surface, the firstmember further including an inlet opening, a first opening, a secondopening, and an outlet opening extending through the first surface, theinlet opening, the first opening, and the second opening beingrespectively in flow communication with the fluid source, the first portof the pump, and the second port of the pump; and a second memberincluding a second surface in contact with the first surface, the secondmember being movable relative to the first member between a firstposition and a second position while maintaining the first and secondsurfaces in contact with each other, the second member being configuredto allow flow communication, respectively, between the inlet opening andthe first opening and between the second opening and the outlet openingin the first position and to allow flow communication, respectively,between the inlet opening and the second opening and between the firstopening and the outlet opening in the second position, wherein at leastone of the first surface and the second surface is made of aself-lubricating material.
 2. The pumping system of claim 1, wherein thefirst surface is made of the self-lubricating material.
 3. The pumpingsystem of claim 2, wherein the first member is made of theself-lubricating material.
 4. The pumping system of claim 1, wherein theself-lubricating material includes polytetrafluoroethylene (PTFE). 5.The pumping system of claim 4, wherein the self-lubricating materialfurther includes at least one of carbon and graphite.
 6. The pumpingsystem of claim 5, wherein the at least one of carbon and graphiteconstitutes 10 to 35% of the self-lubricating material by volume.
 7. Thepumping system of claim 6, wherein the at least one of carbon andgraphite constitutes 20 to 25% of the self-lubricating material byvolume.
 8. The pumping system of claim 1, wherein the valve furthercomprises a valve body including a bore, the first member is a tubularbushing including an inner surface and an outer surface, and the tubularbushing is fitted within the bore of the valve body such that the outersurface of the tubular bushing is in contact with the bore of the valvebody.
 9. The pumping system of claim 8, wherein the second memberincludes a divider and a shaft extending from the divider, and thedivider including an outer surface and the divider is fitted within theinner surface of the tubular bushing so that the outer surface of thedivider and the inner surface of the tubular bushing are, respectively,the second surface and the first surface.
 10. The pumping system ofclaim 8, wherein the tubular bushing includes a first hole formedbetween the inner and outer surfaces, the valve further comprises abonnet secured to the valve body and including a second hole alignedwith the first hole of the tubular bushing, and the valve furthercomprises a pin positioned in the first hole of the tubular bushing andthe second hole of the bonnet to maintain the tubular bushingstationary.
 11. The pumping system of claim 1, wherein the second memberis rotatable between the first position and the second position.
 12. Avalve, comprising: a first member including a first surface, the firstmember further including an inlet opening, a first opening, a secondopening, and an outlet opening extending through the first surface; anda second member including a second surface in contact with the firstsurface, the second member being movable relative to the first memberbetween a first position and a second position while maintaining thefirst and second surfaces in contact with each other, the second memberbeing configured to allow flow communication, respectively, between theinlet opening and the first opening and between the second opening andthe outlet opening in the first position and to allow flowcommunication, respectively, between the inlet opening and the secondopening and between the first opening and the outlet opening in thesecond position, wherein at least one of the first surface and thesecond surface is made of a self-lubricating material.
 13. The valve ofclaim 12, wherein the first surface is made of the self-lubricatingmaterial.
 14. The valve of claim 13, wherein the first member is made ofthe self-lubricating material.
 15. The valve of claim 12, wherein theself-lubricating material includes polytetrafluoroethylene (PTFE). 16.The valve of claim 15, wherein the self-lubricating material furtherincludes at least one of carbon and graphite.
 17. The valve of claim 16,wherein the at least one of carbon and graphite constitutes 10 to 35% ofthe self-lubricating material by volume.
 18. The valve of claim 17,wherein the at least one of carbon and graphite constitutes 20 to 25% ofthe self-lubricating material by volume.
 19. The valve of claim 12,further comprising a valve body including a bore, and wherein the firstmember is a tubular bushing including an inner surface and an outersurface and the tubular bushing is fitted within the bore of the valvebody such that the outer surface of the tubular bushing is in contactwith the bore of the valve body.
 20. The valve of claim 19, wherein thesecond member includes a divider and a shaft extending from the divider,and the divider includes an outer surface and the divider is fittedwithin the inner surface of the tubular bushing so that the outersurface of the divider and the inner surface of the tubular bushing are,respectively, the second surface and the first surface.
 21. The valve ofclaim 19, wherein the tubular bushing includes a first hole formedbetween the inner and outer surfaces, the valve further comprises abonnet secured to the valve body and including a second hole alignedwith the first hole of the tubular bushing, and the valve furthercomprises a pin positioned in the first hole of the tubular bushing andthe second hole of the bonnet to maintain the tubular bushingstationary.
 22. The valve of claim 12, wherein the second member isrotatable between the first position and the second position.
 23. Areplacement kit for a valve, the valve including a divider movablebetween a first position and a second position, the divider including asurface, the replacement kit comprising: a member including a contactsurface, the member further including an inlet opening, a first opening,a second opening, and an outlet opening extending though the contactsurface, the contact surface being made of a self-lubricating materialand configured to be in contact with the surface of the divider whilethe divider moves between the first position where the divider allowsflow communication, respectively, between the inlet opening and thefirst opening and between the second opening and the outlet opening, andthe second position where the divider allows flow communication,respectively, between the inlet opening and the second opening andbetween the first opening and the outlet opening in the second position.24. The replacement kit claim 23, wherein the member is made of theself-lubricating material.
 25. The replacement kit of claim 24, whereinthe self-lubricating material includes polytetrafluoroethylene (PTFE).26. The replacement kit of claim 25, wherein the self-lubricatingmaterial further includes at least one of carbon and graphite.
 27. Thereplacement kit of claim 26, wherein the at least one of carbon andgraphite constitutes 10 to 35% of the self-lubricating material byvolume.
 28. The replacement kit of claim 27, wherein the at least one ofcarbon and graphite constitutes 20 to 25% of the self-lubricatingmaterial by volume.
 29. The replacement kit of claim 23, furthercomprising a valve body including a bore, and wherein the member is atubular bushing including an inner surface and an outer surface and thetubular bushing is fitted within the bore of the valve body such thatthe outer surface of the tubular bushing is in contact with the bore ofthe valve body.
 30. The replacement kit of claim 29, wherein the innersurface of the tubular bushing is sized to fit the divider therewithin.31. The replacement kit of claim 29, wherein the tubular bushingincludes a first hole formed between the inner and outer surfaces, thereplacement kit further comprises a bonnet configured to be secured tothe valve body and including a second hole configured to be aligned withthe first hole of the tubular bushing, and the replacement kit furthercomprises a pin configured to be positioned in the first hole of thetubular bushing and the second hole of the bonnet to maintain thetubular bushing stationary.
 32. A method of manufacturing a replacementkit for a valve, the valve including a divider movable between a firstposition and a second position, the divider including an outer surface,the method comprising: preparing a valve body including a bore, thevalve body further including an inlet hole, a first hole, a second hole,and an outlet hole extending to the bore; preparing a bushing made of aself-lubricating material, the bushing including an outer surface and aninitial inner surface; fitting the bushing within the bore of the valvebody such that the outer surface of the bushing is in contact with thebore of the valve body; and cutting the initial inner surface of thebushing to form a final inner surface sized to be in contact with theouter surface of the divider while the divider moves between the firstposition and the second position.
 33. The method of claim 32, furthercomprising forming an inlet opening, a first opening, a second opening,and a outlet opening through the bushing, the inlet, first, second, andoutlet openings of the bushing being aligned respectively with theinlet, first, second, and outlet holes of the valve body.
 34. The methodof claim 33, further comprising forming a pin hole between the finalinner surface and the outer surface of the bushing.
 35. The method ofclaim 34, further comprising preparing a bonnet configured to be securedto the valve body and forming a second pin hole to be aligned with thepin hole of the bushing when the bonnet is secured to the valve body.